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Convert Joules to Electronvolts

Instantly convert Joules (J) to Electronvolts (eV) with our free online calculator.

Reviewed by Christopher FloiedUpdated

Formula: J to eVmultiply by 6.2415e+18

Reference Table

Joules (J)Electronvolts (eV)
16.241509e+18
53.120755e+19
106.241509e+19
251.560377e+20
503.120755e+20
1006.241509e+20

How to Convert Joules to Electronvolts

Formula

To convert Joules (J) to Electronvolts (eV): multiply by 6.2415e+18

Step-by-Step

  1. Start with your value in Joules (J).
  2. Multiply by 6.2415e+18 to perform the conversion.
  3. The result is your value expressed in Electronvolts (eV).

Conversion Factor

1 J = 6.241509e+18 eV

Reverse Factor

1 eV = 1.602177e-19 J

Worked Example

Convert 25 Joules to Electronvolts: 25 J = 1.560377e+20 eV

About Joule (J)

The SI unit of energy, work, and heat (ISO 80000-5 §5-20), equal to exactly one newton-meter — the energy transferred when a force of one newton acts over a distance of one meter (1 J = 1 N·m = 1 kg·m²/s²). Named for physicist James Prescott Joule, whose 1843-1845 paddle-wheel experiments established the mechanical equivalent of heat (4.184 J ≡ 1 cal) and laid the foundation for the First Law of Thermodynamics. The joule is the universal reference for energy in physics, engineering, chemistry, and biology. Reference scale: a falling apple releases ~1 J; a food Calorie (kcal) is 4,184 J; a AA battery stores ~10,000-15,000 J; a slice of pizza is ~1.2 MJ (300 kcal); a gallon of gasoline ~120 MJ (33 kWh); a US household's daily electricity ~80-100 MJ. Convert J to kWh by dividing by 3,600,000; to calories by dividing by 4.184; to BTU by dividing by 1,055.06; to eV by dividing by 1.602 × 10⁻¹⁹.

About Electronvolt (eV)

A unit of energy equal to the kinetic energy gained by an electron accelerating through an electric potential difference of one volt in vacuum, defined since the 2019 SI redefinition as exactly 1.602176634 × 10⁻¹⁹ joules (CODATA 2018, BIPM SI Brochure). The electronvolt is the natural working unit of atomic, molecular, and particle physics where joules are too large to be convenient: chemical bond energies are a few eV (C-C bond ~3.6 eV, O-H bond ~4.8 eV), photon energies in the visible spectrum are 1.6-3.1 eV (red to violet), X-rays carry keV (medical diagnostic ~80-140 keV, hard X-ray ~10-100 keV), nuclear-reaction Q-values are MeV (fission of U-235 releases ~200 MeV per atom), particle-collider beam energies are GeV-TeV (LHC operates at 13.6 TeV center-of-mass), and astrophysical sources reach PeV / EeV (highest-energy cosmic rays ~3 × 10²⁰ eV = 300 EeV). Particle physics papers in Physical Review D, JHEP, Nature Physics, and the PDG Review of Particle Physics report all energies, masses (E = mc² gives a free conversion), and cross-sections in eV or its derivatives. 1 eV ≈ 1.602 × 10⁻¹⁹ J ≈ 1.602 × 10⁻¹² erg.

Quick Facts

  • 1 Joule equals 6.241509e+18 Electronvolts
  • 1 Electronvolt equals 1.602177e-19 Joules
  • Joule is a unit of energy
  • Electronvolt is a unit of energy
  • This conversion is commonly used in nutrition, electrical billing, physics, and mechanical engineering
  • The Joule belongs to the metric system

Common Joule to Electronvolt Conversions

Joules (J)Electronvolts (eV)
0.016.241509e+16
0.16.241509e+17
0.251.560377e+18
0.53.120755e+18
16.241509e+18
21.248302e+19
31.872453e+19
53.120755e+19
106.241509e+19
159.362264e+19
201.248302e+20
251.560377e+20
503.120755e+20
754.681132e+20
1006.241509e+20
2501.560377e+21
5003.120755e+21
10006.241509e+21
50003.120755e+22
100006.241509e+22

Understanding Joules

The Joule (symbol: J) is a unit of energy. The SI unit of energy, work, and heat (ISO 80000-5 §5-20), equal to exactly one newton-meter — the energy transferred when a force of one newton acts over a distance of one meter (1 J = 1 N·m = 1 kg·m²/s²). Named for physicist James Prescott Joule, whose 1843-1845 paddle-wheel experiments established the mechanical equivalent of heat (4.184 J ≡ 1 cal) and laid the foundation for the First Law of Thermodynamics. The joule is the universal reference for energy in physics, engineering, chemistry, and biology. Reference scale: a falling apple releases ~1 J; a food Calorie (kcal) is 4,184 J; a AA battery stores ~10,000-15,000 J; a slice of pizza is ~1.2 MJ (300 kcal); a gallon of gasoline ~120 MJ (33 kWh); a US household's daily electricity ~80-100 MJ. Convert J to kWh by dividing by 3,600,000; to calories by dividing by 4.184; to BTU by dividing by 1,055.06; to eV by dividing by 1.602 × 10⁻¹⁹.

It belongs to the metric measurement system.

Joules are commonly used in nutrition, electrical billing, physics, and mechanical engineering.

Understanding Electronvolts

The Electronvolt (symbol: eV) is a unit of energy. A unit of energy equal to the kinetic energy gained by an electron accelerating through an electric potential difference of one volt in vacuum, defined since the 2019 SI redefinition as exactly 1.602176634 × 10⁻¹⁹ joules (CODATA 2018, BIPM SI Brochure). The electronvolt is the natural working unit of atomic, molecular, and particle physics where joules are too large to be convenient: chemical bond energies are a few eV (C-C bond ~3.6 eV, O-H bond ~4.8 eV), photon energies in the visible spectrum are 1.6-3.1 eV (red to violet), X-rays carry keV (medical diagnostic ~80-140 keV, hard X-ray ~10-100 keV), nuclear-reaction Q-values are MeV (fission of U-235 releases ~200 MeV per atom), particle-collider beam energies are GeV-TeV (LHC operates at 13.6 TeV center-of-mass), and astrophysical sources reach PeV / EeV (highest-energy cosmic rays ~3 × 10²⁰ eV = 300 EeV). Particle physics papers in Physical Review D, JHEP, Nature Physics, and the PDG Review of Particle Physics report all energies, masses (E = mc² gives a free conversion), and cross-sections in eV or its derivatives. 1 eV ≈ 1.602 × 10⁻¹⁹ J ≈ 1.602 × 10⁻¹² erg.

Electronvolts are commonly used in nutrition, electrical billing, physics, and mechanical engineering.

Why Convert Joules to Electronvolts?

Converting energy between Joules and Electronvolts is common in physics, nutrition, and engineering. Electricity bills use kilowatt-hours, food labels list calories or kilojoules, and mechanical engineers work with joules and BTUs. Reliable conversion helps professionals and consumers compare energy values across different contexts.

Frequently Asked Questions

How do I convert Joules to Electronvolts?

The SI unit of energy, work, and heat (ISO 80000-5 §5-20), equal to exactly one newton-meter — the energy transferred when a force of one newton acts over a distance of one meter (1 J = 1 N·m = 1 kg·m²/s²). To convert Joules to Electronvolts, multiply by 6.2415e+18. For example, 25 J equals 1.560377e+20 eV.

How many Electronvolts are in 1 Joule?

There are 6.241509e+18 Electronvolts in 1 Joule.

How many Joules are in 1 Electronvolt?

There are 1.602177e-19 Joules in 1 Electronvolt.

What is the formula for Joule to Electronvolt conversion?

The formula is: multiply by 6.2415e+18. This means 1 J = 6.241509e+18 eV.

Is a Joule bigger than a Electronvolt?

No. One Joule is smaller than one Electronvolt because 1 J equals 6.241509e+18 eV, which is greater than 1.

When do you need to convert between Joules and Electronvolts?

A unit of energy equal to the kinetic energy gained by an electron accelerating through an electric potential difference of one volt in vacuum, defined since the 2019 SI redefinition as exactly 1. Joule and Electronvolt are both energy units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.

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